T7 RNA polymerase (T7 RNAP) is one of the simplest known RNA polymerases. Its unique structural features make it a critical model for studying the mechanisms of RNA synthesis. This review systematically examines the static crystal structure of T7 RNAP, beginning with an in-depth examination of its characteristic “thumb”, “palm”, and “finger” domains, which form the classic “right-hand-like” architecture. By detailing these structural elements, this review establishes a foundation for understanding the overall organization of T7 RNAP. This review systematically maps the functional roles of secondary structural elements and their subdomains in transcriptional catalysis, progressively elucidating the fundamental relationships between structure and function. Further, the intrinsic flexibility of T7 RNAP and its applications in research are also discussed. Additionally, the review presents the structural diagrams of the enzyme at different stages of the transcription process, and through these diagrams, it provides a detailed description of the complete transcription process of T7 RNAP. By integrating structural dynamics and kinetics analyses, the review constructs a comprehensive framework that bridges static structure to dynamic processes. Despite its advantages, T7 RNAP has a notable limitation: it generates double-stranded RNA (dsRNA) as a byproduct. The presence of dsRNA not only compromises the purity of mRNA products but also elicits nonspecific immune responses, which pose significant challenges for biotechnological and therapeutic applications. The review provides a detailed exploration of the mechanisms underlying dsRNA formation during T7 RNAP catalysis, reviews current strategies to mitigate this issue, and highlights recent progress in the field. A key focus is the semi-rational design of T7 RNAP mutants engineered to minimize dsRNA generation and enhance catalytic performance. Beyond its role in transcription, T7 RNAP exhibits rapid development and extensive application in fields, including gene editing, biosensing, and mRNA vaccines. This review systematically examines the structure-function relationships of T7 RNAP, elucidates the mechanisms of dsRNA formation, and discusses engineering strategies to optimize its performance. It further explores the engineering optimization and functional expansion of T7 RNAP. Furthermore, this review also addresses the pressing issues that currently need resolution, discusses the major challenges in the practical application of T7 RNAP, and provides an outlook on potential future research directions. In summary, this review provides a comprehensive analysis of T7 RNAP, ranging from its structural architecture to cutting-edge applications. We systematically examine: (1) the characteristic right-hand domains (thumb, palm, fingers) that define its minimalistic structure; (2) the structure-function relationships underlying transcriptional catalysis; and (3) the dynamic transitions during the complete transcription cycle. While highlighting T7 RNAP’s versatility in gene editing, biosensing, and mRNA vaccine production, we critically address its major limitation—dsRNA byproduct formation—and evaluate engineering solutions including semi-rationally designed mutants. By synthesizing current knowledge and identifying key challenges, this work aims to provide novel insights for the development and application of T7 RNAP and to foster further thought and progress in related fields.

Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by progressive cognitive decline, functional impairment, and neuropsychiatric symptoms. It represents the most prevalent form of dementia among the elderly population. Accumulating evidence indicates that oxidative stress plays a pivotal role in the pathogenesis of AD. Notably, elevated levels of oxidative stress have been observed in the brains of AD patients, where excessive reactive oxygen species (ROS) can cause extensive damage to lipids, proteins, and DNA, ultimately compromising neuronal structure and function. Amyloid β‑protein (Aβ) has been shown to induce mitochondrial dysfunction and calcium overload, thereby promoting the generation of ROS. This, in turn, exacerbates Aβ aggregation and enhances tau phosphorylation, leading to the formation of two pathological features of AD: extracellular Aβ plaque deposition and intracellular neurofibrillary tangles (NFTs). These events ultimately culminate in neuronal death, forming a vicious cycle. The interplay between oxidative stress and these pathological processes constitutes a core link in the pathogenesis of AD. The signaling pathways mediating oxidative stress in AD include Nrf2, RCAN1, PP2A, CREB, Notch1, NF‑κB, ApoE, and ferroptosis. Nrf2 signaling pathway serves as a key regulator of cellular redox homeostasis, exerts important antioxidant capacity and protective effects in AD. RCAN1 signaling pathway, as a calcineurin inhibitor, and modulates AD progression through multiple mechanisms. PP2A signaling pathway is involved in regulating tau phosphorylation and neuroinflammation processes. CREB signaling pathway contributes to neuroplasticity and memory formation; activation of CREB improves cognitive function and reduce oxidative stress. Notch1 signaling pathway regulates neuronal development and memory, participates in modulation of Aβ production, and interacts with Nrf2 toco-regulate antioxidant activity. NF‑κB signaling pathway governs immune and inflammatory responses; sustained activation of this pathway forms “inflammatory memory”, thereby exacerbating AD pathology. ApoE signaling pathway is associated with lipid metabolism; among its isoforms, ApoE-ε4 significantly increases the risk of AD, leading to elevated oxidative stress, abnormal lipid metabolism, and neuroinflammation. The ferroptosis signaling pathway is driven by iron-dependent lipid peroxidation, and the subsequent release of lipid peroxidation products and ROS exacerbate oxidative stress and neuronal damage. These interconnected pathways form a complex regulatory network that regulates the progression of AD through oxidative stress and related pathological cascades. In terms of therapeutic strategies targeting oxidative stress, among the drugs currently used in clinical practice for AD treatment, memantine and donepezil demonstrate significant therapeutic efficacy and can improve the level of oxidative stress in AD patients. Some compounds with antioxidant effects (such asα-lipoic acid and melatonin) have shown certain potential in AD treatment research and can be used as dietary supplements to ameliorate AD symptoms. In addition, non-drug interventions such as calorie restriction and exercise have been proven to exerted neuroprotective effects and have a positive effect on the treatment of AD. By comprehensively utilizing the therapeutic characteristics of different signaling pathways, it is expected that more comprehensive multi-target combination therapy regimens and combined nanomolecular delivery systems will be developed in the future to bypass the blood-brain barrier, providing more effective therapeutic strategies for AD.

Objective: To investigate the detection of depressive symptoms and its influencing factors among middle school students in Huzhou City, so as to provide insights for improving the mental health levels among middle school students. Methods: From September to November 2024, a total of 4 729 middle school students from five counties (districts) in Huzhou City were selected through the stratified cluster random sampling method. Demographic information, lifestyle, and school bullying were collected through questionnaire surveys. Depressive symptoms were assessed using the Center for Epidemiological Studies Depression Scale (CES-D). Factors affecting depressive symptoms among middle school students were analyzed using a multivariable logistic regression model. Results: A total of 4 729 middle school students were surveyed, including 2 200 boys (46.52%) and 2 529 girls (53.48%). Depressive symptoms were detected in 1 026 students, with a detection rate of 21.70%. Multivariable logistic regression analysis showed that girl (OR=1.960, 95%CI: 1.659-2.317), high school (ordinary high school, OR=1.789, 95%CI: 1.465-2.186; vocational high school, OR=1.581, 95%CI: 1.105-2.263), consumption of sugar-sweetened beverages >0 time/day (<1 time/day, OR=1.363, 95%CI: 1.009-1.841; ≥1 time/day, OR=1.568, 95%CI: 1.098-2.239), fried food intake ≥1 time/day (OR=1.890, 95%CI: 1.291-2.769), skipping breakfast daily (OR=2.178, 95%CI: 1.825-2.599), TV viewing time ≥2 hours/day (OR=1.457, 95%CI: 1.154-1.838), insufficient sleep duration (OR=1.761, 95%CI: 1.422-2.181), smoking (OR=2.798, 95%CI: 1.834-4.269), alcohol consumption (OR=2.282, 95%CI: 1.861-2.798), experiencing school bullying (OR=5.440, 95%CI: 3.148-9.402) and parental physical/verbal abuse (OR=3.954, 95%CI: 3.189-4.902) were associated with a higher risk of depressive symptoms among middle school students. Conversely, the middle school students who engaged in moderate-to-vigorous physical activity ≥3 times/week (OR=0.784, 95%CI: 0.668-0.921) and attended physical education classes ≥3 sessions/week (OR=0.736, 95%CI: 0.613-0.884) were associated with a lower risk of depressive symptoms. Conclusion The prevalence of depressive symptoms among middle school students in Huzhou City was lower than national average, and was influenced by dietary habits, physical exercise, sleep duration, smoking, alcohol consumption, and experiencing school bullying.

AIM To evaluate the quality consistency of Tongmai Granules,Tongmai Tablets,Tongmai Capsules and Tongmai Oral Liquid.METHODS The HPLC fingerprints were established,after which the contents of danshensu,protocatechuic aldehyde,3'-hydroxy puerarin,puerarin,puerarin apioside,daidzin,ferulic acid,salvianolic acid B and salvianolic acid A were determined,and cluster analysis and principal component analysis were adopted in the quality analysis from the perspective of daily intake.RESULTS There were 21 common peaks in the fingerprints for 39 batches of samples with the similarities of 0.765-0.997.Various batches of samples were clustered into 5 categories,2 principal components demonstrated the accumulative variance contribution rate of 83.53％ .The daily intakes of various constituents in different dosage forms exhibited obvious differences,especially for that of salvianolic acid B,which were low in tablets and capsules,and their heterogeneities existed among the same dosage forms.CONCLUSION This simple and accurate method can provide a reference for the quality evaluation of Tongmai preparations from different manufacturers.

To formulate an expert consensus on the principles of preoperative hair removal and provide scientific guidance for standardized removal of hair before surgical procedures so as to reduce the incidence of surgical site infections.METHODS Led by the Hospital Management Institute of National Health Commission of the People's Republic of China,this consensus was reached with the joint efforts from the expects of relevant fields such as surgeries,interventional therapies,nursing,and infection prevention and control.The consensus facilitates the classification and evaluation of literatures by following the evidence grade formulated by Oxford Evidence-based Medicine Center and focuses on the association of preoperative hair removal with surgical site infection,it reaches the evidence grade of expert consensus and recommendation intensity by integrating with discussions on meetings and clinical experience of the expects from relevant fields.RESULTS A total of 6 items of consensus were reached by summarizing the latest evidence on the aspects including the indications for preoperative hair removal,tools,range,timing and places.CONCLUSION The consensus,to some extent,make supplements to and complete the exiting regulations and standards.It provides guidance for the medical institutions to carry out the preoperative hair removal.

Aim To investigate the neuroprotective effect of Takeda G protein-coupled receptor-5(TGR5)activated by INT-777 on hypoxic-ischemic encephalop-athy(HIE)in neonatal rats.Methods Seven-day-old SD rats were randomly divided into the sham opera-tion group(Sham,S),model group(HIE,G),INT-777 low-dose(L),medium-dose(M),and high-dose(H)groups.The modified Rice-Vanucci method was used to construct the HIE model and Intranasal admin-istration 1 h after modeling.Short-term neurobehavioral tests were performed 48 h after modeling to evaluate the neurological function of neonatal rats,TTC staining was used to determine the volume of cerebral infarction,dry and wet specific gravity was used to determine the brain water content,ferrous ion kit was used to deter-mine the brain ferrous ion content,HE staining was used to observe the pathological damage of brain tis-sue,Nissl staining was used to observe the loss of Nissl substance,Transmission electron microscopy(TEM)was used to observe the mitochondrial morphological changes of cortical neurons,and Western blot was em-ployed to detect the expression of ferroptosis-related proteins TFR1 and GPX4.Results Compared with group S,group G had increased short-term neurobehav-ioral test consumption time,higher scores,increased cerebral infarct volume,brain water content,and brain ferrous iron content,significant brain tissue damage on the affected side,severe loss of Nissl substance,smaller neuronal mitochondria,decreased mitochondrial cris-tae,and increased expression of TFR1 and reduced ex-pression of GPX4.Compared with group G,the INT-777 administration group had a shorter consumption time for short-term neurobehavioral tests,lower scores,the cerebral infarction volume,brain water content,and brain ferrous ion content decreased,the brain tissue damage on the affected side was reduced,and there was insignificant loss of Nissl substance,larger neuronal mi-tochondrial volume,increased mitochondrial cristae,re-duced expression of TFR1,and increased expression of GPX4.Conclusions INT-777 agonist TGR5 has a protective effect against hypoxic-ischemic encephalopa-thy in neonatal rats,and its mechanism of action may be related to the inhibition of neuronal ferroptosis.

Aim To explore the mechanism of action of Guizhi Jia Gegen decoction(GGD)in treating pneu-monia-enteritis induced by H1N1 influenza virus infec-tion in a mouse model,using network pharmacology and molecular docking techniques,followed by in vivo verification.Methods A pneumonia-enteritis mouse model was established,and the intervention effects of GGD on the model mice were evaluated using indica-tors such as body weight,rectal temperature,lung in-dex,colon length,H1N1 M gene expression,relative mRNA expression levels of inflammatory cytokines,and pathological sections of the lung and intestine.The targets of the blood-absorbed components of GGD were identified using the Swiss Target Prediction platform,and the disease targets were retrieved from the Gene-Cards platform.The intersecting targets were analyzed through PPI network analysis using the STRING data-base to identify core targets.GO analysis and KEGG pathway enrichment analysis were performed using the Metascape database.RT-qPCR was employed to vali-date the core targets and pathways.Molecular docking was conducted using AutoDock Tools software to verify the interactions between blood-absorbed components and key targets.Results GGD demonstrated signifi-cant therapeutic effects on the pneumonia-enteritis mouse model.The results of network pharmacology in-dicated that the therapeutic effects of GGD were strong-ly associated with targets such as TNF,ALB,PTGS2,MMP9,EGFR,ESR1,SRC,HSP90AA1,PPARG and MMP2.RT-qPCR results indicated that GGD could intervene in pneumonia-enteritis by regulating the targets TNF,ALB,EGFR and the related targets of the NF-κB pathway.Molecular docking results re-vealed that blood-absorbed components such as puerar-in and liquiritin could stably bind to TNF,ALB and EGFR.Conclusion Components such as puerarin and liquiritin in GGD may exert therapeutic effects on pneumonia-enteritis induced by H1N1 influenza virus infection by acting on targets such as TNF,ALB and EGFR.

Objective To evaluate the safety and feasibility of percutaneous mitral balloon valvuloplasty with the assistance of arterio-venous circuit.Methods From January 2015 to October 2022,a total 25 patients[19 females,6 males;age(61.60±9.00)years]were included,who were diagnosed with rheumatic heart disease and severe mitral stenosis.A transseptal puncture was performed to establish a femoral arterio-venous circuit,followed by graded dilation with Inoue balloon(diameters:22.00 mm to 28.00 mm).The target was a mitral valve area≥1.50 cm2 with mild or less regurgitation.Results The arterio-venous circuit was established,and mitral balloon valvuloplasty was successfully completed in all 25 patients.Among them,20 patients experienced difficulty with transvalvular crossing using the balloon catheter with conventional methods,16 patients had valvular severe calcification,and 3 patients presented with a left atrial appendage thrombus despite of more than 6-month anticoagulation therapy with warfarin.The mean balloon diameter was(25.00±1.40)mm.The mitral valve area increased from(0.91±0.15)cm2 preoperatively to(1.70±0.14)cm2 postoperatively(P＜0.001).Mean left atrial pressure decreased from(27.00±7.50)mmHg to(16.36±4.07)mmHg(P＜0.001),and mean pulmonary artery pressure decreased from(40.84±13.81)mmHg to(25.00±7.12)mmHg(P＜0.001).All patients showed significant symptom improvement with no complications.Conclusions Arterio-venous circuit for percutaneous mitral balloon valvuloplasty is safe and feasible.This technique can serve as an alternative to standard technique for patients with complex mitral stenosis.

Objective To propose a preventive maintenance strategy of the heating,ventilation and air-conditioning(HVAC)system in pharmacy intravenous admixture services(PIVAS)based on the reliability centered maintenance(RCM)method so as to provide references for PIVAS equipment maintenance.Methods Firstly,a HVAC system RCM review team was formed,and the failure modes and impacts of important functional components of the equipment were analyzed to clarify the consequences of the failure of each functional component under the premise of ensuring the safety and integrity of the equipment and with the goal of minimizing the loss of maintenance downtime and the consumption of maintenance resources.Secondly,with a standardized logical decision-making procedure the preventive maintenance strategy was determined and implemented based on the consequences of functional failure.Finally,statistical analyses were carried out on such equipment indicators as performance parameter qualification rate,failure rate and maintenance cost before and after the RCM method-based strategy was executed,in order to evaluate the efficacy of the strategy.Results The RCM method-based preventive maintenance strategy had the performance qualification rate increased from 97.47%to 99.06%(χ2=24.139,P<0.01),the failure rate decreased from 0.24%to 0.03%(χ2=13.519,P<0.01)and the maintenance cost reduced by 11.5%,from RMB 134,200 to 118,700.Conclusion The RCM method-based preventive maintenance strategy provides reliable equipment for PIVAS and lowers the maintenance cost effectively,and references are given for the development of automated and intelligent equipment maintenance strategies for PIVAS.[Chinese Medical Equipment Journal,2025,46(10):78-83]

CRM 197(cross-reacting material 197),a naturally occurring mutant of diphtheria toxin,is a safe and effective vaccine vector and extensively used on developing conjugate or combined vaccines.The mutant loses its enzymatic activity,but fully retains its receptor-binding ability and immunogenicity.In current work,the diphtheria toxin mutant CRM 197 and its fusion proteins with the receptor-binding do-main of botulinum neurotoxin serotype E(EHc)were developed using genetic engineering technology.These recombinant proteins were confirmed by Western blotting and SDS-PAGE.BALB/c mice were im-munized with the CRM197-EHc and EHc-CRM197 fusion proteins,and their immunogenicity was evalua-ted.These two fusion protein molecules,CRM197-EHc and EHc-CRM197,as subunit vaccines,elicited a robust humoral immune response targeting both CRM197 and EHc antigens in the immunized mice.Compared to the mixture of CRM197 and EHc,the mice vaccinated with the fusion proteins(CRM197-EHc and EHc-CRM197)induced higher levels of anti-CRM197 antibodies,and the mice vaccinated with EHc-CRM197 also generated strongest anti-EHc antibodies.Consequently,as a carrier molecule in the fusion protein vaccine,EHc enhances the immunogenicity of CRM197 molecules.Likewise,CRM197 boosts the immunogenicity of EHc in the EHc-CRM197 fusion protein.